1. Field of the Invention
The present invention generally relates to storage vessels and related closure techniques. More specifically, the present invention relates to storage vessels which facilitate the use of non-welded closure techniques for sealing the storage vessels and related methods.
2. Description of the Related Art
Nuclear fuel discharged from fission reactors, referred to hereinafter as Spent Nuclear Fuel (SNF), typically is stored in deep pools filled with water, with the water being provided to dissipate heat and to attenuate gamma and neutron radiation generated by the SNF. As an alternative to storing SNF in water-filled pools (xe2x80x9cwet storagexe2x80x9d), xe2x80x9cdry storagexe2x80x9d techniques also have been utilized.
In a typical dry-storage application, the SNF is stored in a substantially horizontal or substantially vertical configuration within a protective vessel, such as a xe2x80x9ccaskxe2x80x9d or xe2x80x9coverpack,xe2x80x9d which typically includes a heavy-walled structure. Additionally, the SNF may be stored in a thin-walled vessel (referred to hereinafter as a canister) which then may be placed into a cask. Such dry storage applications are widely viewed as possessing the necessary characteristics to enable economical long-term storage of SNF.
Typically, a cylindrical canister utilized in dry-storage applications incorporates two lids, in addition to a bottom closure, for promoting a final sealing of the canister. These two lids are utilized for providing redundancy as well as enhancing protection against leakage of internally stored contents. Heretofore, each of the lids typically is welded to the shell of the canister with the welding of the lids typically being performed at the location where the SNF is loaded into the canister, such as at a nuclear facility. Typically, in order to facilitate sealing of the canister by welding, special welding, testing, and inspection equipment is made available and specially trained and qualified personnel are utilized to assure that high quality welds for sealing the lids to the canister shell are achieved. Thus, welding of the lids typically is a very expensive and time intensive process that may potentially result in increased radiation exposure to personnel, e.g., the personnel performing the welding.
Therefore, there is a need for improved storage systems and methods which address these and other shortcomings of the prior art.
Briefly described, the present invention relates to storage vessels and related closure techniques. More specifically, the present invention relates to storage vessels which facilitate the use of non-welded closure techniques for sealing the storage vessels and related methods. In this regard, a preferred embodiment of the present invention may be construed as providing a storage system which includes a container, a closure lid, and a compression link. Preferably, the container includes an outer wall, which defines an interior, and a first open end. The closure lid is configured to be inserted within the open end of the container, and is adapted to engage in a sealing relationship with the outer wall of the container. Preferably, the compression link includes a container engagement surface and a closure lid engagement surface. The compression link is configured to engage between the closure lid and the outer wall of the container to retain the closure lid in sealing engagement with the container. The container engagement surface and the closure lid engagement surface are configured to extend outwardly from each other, with the container engagement surface being adapted to engage the outer wall of the container and the closure lid engagement surface being adapted to engage the closure lid. So configured, the closure lid may be retained in sealing engagement with the outer wall.
In some embodiments, a material, such as spent nuclear fuel, for example, may be inserted within the container and sealed therein.
In another embodiment, the storage system includes a container, a closure lid, and means for retaining the closure lid in sealing engagement with the outer wall.
Some embodiments may be construed as providing methods for storing a material. In a preferred embodiment, the method comprises the steps of: (1) providing a container having a first open end and defining an interior; (2) providing a closure lid adapted to be received within the open end; and (3) sealing the closure lid to the container by placing a portion of the closure lid under compression and a corresponding portion of the outer wall under tension.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such features and advantages be included herein within the scope of the present invention, as defined in the appended claims.